Closure for the metered dispensing of adhesive from a container

Abstract

In order to manufacture a closure having an improved seal and lower degree of wear at more reasonable cost, a closure is proposed, the closure comprising an upper part ( 5 ), a lower part ( 4 ) and a conveying sleeve ( 6 ) with a sealing pin ( 65 ). On the lower part ( 4 ) there are two concentric, upwardly directed annular walls ( 48 ) which interact under prestress with two corresponding, concentrically downwardly directed annular walls ( 500 ) on the upper part ( 5 ), which annular walls are directed downwards. The lower part ( 4 ) and the conveying sleeve ( 6 ) can be manufactured integrally via predetermined breaking point bridges ( 600 ), thus making it possible to obtain a cost-saving method of assembly.

1 . A closure for the metered dispensing of adhesive from a container, wherein the closure comprises:
 (a) a lower part that can be attached to the container in a sealing fashion and having a peripheral jacket wall transforming into a first annular shoulder that is directed toward the center,   (b) an upper part that forms a cap that is rotatably held on the lower part and having a jacket wall, the top of which is provided with a second annular shoulder that is directed toward the center and centrally tapered such that an outlet nozzle is formed, and   (c) a conveying sleeve with a central sealing pin that is separated from the lower part and the upper part in the assembled state, wherein said conveying sleeve is supported in the lower part in a sliding and non-rotatable fashion and moves in an internal thread in the upper part such that the sealing pin can be transferred from an upper closed position into a lower open position and vice versa by turning the upper part in the outlet nozzle,   wherein two concentric, outwardly directed annular walls are arranged on the first shoulder of the lower part, and two concentric annular walls are arranged on the upper part such that they are directed downward on the underside of the second shoulder, and wherein pairs of the concentric walls respectively form sliding seals that adjoin one another under preload.   
   
   
       2 . The closure according to  claim 1 , wherein the ends of the concentric annular walls on the upper part have peripheral annular beads that are directed outward and adjoin the lower part under preload on the inner sides of the concentric annular walls. 
   
   
       3 . The closure according to  claim 1 , wherein the concentric annular walls on the lower part have inwardly protruding annular beads that adjoin the upper part under prestress on the outer side of the concentric annular walls. 
   
   
       4 . The closure according to  claim 3 , wherein the preload is generated due to the thickness of the annular beads. 
   
   
       5 . The closure according to  claim 1 , wherein the upper region of the conveying sleeve has an external thread that cooperates with an internal thread arranged in a sleeve-shaped attachment between the second shoulder of the upper part and the outlet nozzle. 
   
   
       6 . The closure according to  claim 5 , wherein at least two guide ribs are moulded on the conveying sleeve underneath the external thread such that they protrude radially outward, and the first shoulder has notches, in which the at least two guide ribs are positively supported in a sliding fashion in order to prevent a rotation thereof. 
   
   
       7 . The closure according to  claim 1 , wherein the sealing pin is held in the conveying sleeve by means of supports that extend from the inner wall of the conveying sleeve to the center. 
   
   
       8 . The closure according to  claim 6 , wherein the sleeve-shaped attachment has a plane, annular stop underneath the internal thread, and the guide ribs contact the stop in the closed state of the closure. 
   
   
       9 . A semi-finished product for manufacturing a closure according to  claim 1 , wherein the semi-finished product consists of the lower part and the conveying sleeve, and the lower part and the conveying sleeve are manufactured in one piece and connected by means of predetermined breaking point bridges. 
   
   
       10 . The semi-finished product according to  claim 9 , wherein the upper region of the conveying sleeve features an external thread and at least two guide ribs are moulded on the conveying sleeve such that they protrude radially outward, and the first shoulder has notches that are adapted to the cross-sectional shape of the at least two guide ribs, and wherein the predetermined breaking point bridges are moulded on the lower edge of the guide ribs on one side and on the edge of the notches on the other side. 
   
   
       11 . The semi-finished product according to  claim 9 , wherein a stopping rib that protrudes radially outward is moulded on the outer side of the jacket wall of the lower part, wherein a stopping element is injection-moulded on the inner side of the upper part, and wherein the stopping rib and the stopping element jointly limit the rotation between the upper part and the lower part in an assembled state of the closure. 
   
   
       12 . The semi-finished product according to  claim 11 , wherein a window is arranged in the jacket wall of the upper part in a predetermined angular position to the stopping element, and wherein a scale is arranged on the lower part and indicates the rotation of the upper part relative to the lower part in relation to the position, in which the stopping rib and the stopping element are in contact with one another in the assembled state. 
   
   
       13 . An assembly method for manufacturing a closure according to  claim 1  using a semi-finished product consisting of the lower part and the conveying sleeve, the lower part and the conveying sleeve being manufactured in one piece and connected by means of predetermined breaking point bridges, wherein the upper part features a sleeve-shaped attachment ( 54 ) between the second shoulder and an outlet nozzle, wherein the center axis of the semi-finished product with its conveying sleeve is axially aligned with the center axis of the attachment and the semi-finished product is then screwed into the sleeve-shaped attachment of the upper part until the guide ribs contact the conveying sleeve underneath the sleeve-shaped attachment, wherein the predetermined breaking point bridges are now separated due to a collision movement and the upper part with the conveying sleeve screwed into the sleeve-shaped attachment is pushed downward to such a degree that the concentric annular walls on the upper part and the lower part slide on one another under a certain prestress and are moved into a preloaded position. 
   
   
       14 . The assembly method according to  claim 13 , wherein the upper part and the semi-finished product are screwed together with a predetermined torque and while monitoring said torque such that a stopping element on the upper part and a stopping rib on the lower part are moved into an approximately contacting position relative to one another after the collision movement once a predetermined torque is reached. 
   
   
       15 . The assembly method according to  claim 13 , wherein the semi-finished product is attached to a rotatively driven holding finger before the semi-finished product and the upper part are screwed together. 
   
   
       16 . The assembly method according to  claim 15 , wherein the holding finger has notches with such dimensions that supports holding the sealing pin of the conveying sleeve can be at least in part positively accommodated therein, wherein the semi-finished product is attached and the holding finger carries out a certain rotation while the semi-finished product is non-rotationally fixed, until the aforementioned supports engage into the notches of the holding finger.